This application details a plan to build from and expand the work of the currently funded Chicago Center for Youth Violence Prevention (U01 CE001949-05) through the collaboration of researchers and a coalition of faith and community leaders to support a community initiated effort to reduce youth crime and violence within a target high-risk community in Chicago. Building from both the success and lessons learned from the currently funded Center, the focus of the approach proposed in this application is to move from the study of the individual and collective impact of a set of preventive interventions delivered within a single community to the implementation and evaluation of a community-level prevention system. In addition, building from previous work of this group of investigators, data from the Illinois Violent Death Reporting System and administrative data gathered from city data archives will be used to evaluate policy-level prevention strategies that are currently being implemented in the target and other high burden communities in Chicago. These data will also be used to conduct a series of studies to inform policies to reduce and prevent youth and other forms of violence. This combination of activities is designed to address critical gaps in the field and buil the evidence-base regarding effective community and policy-level prevention strategies to achieve community-level impact on youth and other forms of violence. The Center's primary aims are: 1) to build a coalition of community, policy and academic partners to address the issues of youth and other forms of violence within Chicago neighborhoods; 2) to evaluate the process and impact of implementing a community-level prevention system (Communities that Care) in a high-risk urban community and to identify unique challenges and adaptations necessary for implementation in urban neighborhoods; 3) to evaluate the diffusion and impact of CTC on neighborhood social organization and processes (i.e., collective efficacy, social organization, connection and support, norms and attitudes toward violence), processes that have been empirically linked with youth and other forms of violence; 4) to evaluate and inform current policy strategies aimed at reducing youth and other forms of violence; 5) to provide training and technical assistance to build capacity for schools and community agencies to select and implement evidence-based interventions and to evaluate existing interventions within the community; and 6) to disseminate empirical findings regionally and nationally to scientific, practice and policy communities.